Blood transfusion syringe



Nov. 29, 1938. R. P. LANDls l BLOOD TRANSFUSION SYRINGE Filed Nov. 16,1936 INVEITOR I?. I? L andas Patented Nov. 29, 1938 PATENT OFFICE BLOOD*TRANSFUSION SYRINGE? Richard P. Landis, Grass Valley, Calif., assignerto Landis Transfusion Equipment Co., Sacramento, Calif., a corporationof California Application November 16, 1936, Serial No. 111,048

3 Claims.

This invention relates generally to a blood transfusion syringe and inparticular relates to improvements in the flow control valves of suchsyringes shown Vin my United States Patent No.

2,057,726, issued October 20th, 1936.

The principal object of the present invention is to provide a syringecap and valve construction for blood transfusion syringes in which thevalves employed are of an improved form, such improved form of valvebeing inexpensive to manufacture and yet very effective to preventregurgitation of blood from the recipient to donor during a transfusion.

A further object of this invention is to mount the check valves in thesyringe cap in such manner that the valves may be readily removed'forcleaning and sterilization.

A further object of the invention is to produce a simple and inexpensivedevice and yet one which will be exceedingly effective for the purposefor which it is designed.

These objects I accomplish by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims. v

In the drawing similar characters of reference indicate correspondingparts in the several views:

Figure 1 is an elevation, mainly in section, of the valve supporting capas attached to one end of a standard glass, plunger type, syringe.

Figure 2 is an inner end view of the cap.

Referring now more particularly to the characters of reference on thedrawing, the device comprises a relatively thick cap I of suitablematerial having a tapped skirt 2 for threaded but removable connectionwith a ring 3 secured to one end of a glass, plunger type, syringe 1I.The engaging faces of the cap I and the inwardly projecting flange 5 ofring 3, are carefully machined so that a tight connection is assuredWithout the use of a gasket. The syringe plunger is indicated at 6.

The cap I is formed with a pair of spaced, longitudinally extending,cylindrical bores 'I and 8. Oppositely facing check valves are disposedin said bores, the valves being constructed and mounted in the followingmanner: Each valve is made of soft resilient rubber and comprises acylindrical body 9 freely open at one end and formed at the other endwith converging, self closing and 5o normally closed lips I0. These lipsare designed so that they will open apart, to permit of a flowtherethrough, only with pressure inside the valve. An annular flange IIis formed with and surrounds each valve body at said one end, the bore55 for each valve being enlarged from the adjacent (Cl. 12S-214) end ofthe cap as at I2, and to a depth greater than the thickness of theflange, to receive and form a seat for such flange. v

The inward opening valve in bore 'I is the intake valve and is secur-edin place by means of a collar 5 I3 on the base of the intake i'lttingI4, which is threaded into the outer end of the corresponding enlargedbore I2, and engaging flange Il of the valve, to press the same rmlyonto its s eat and prevent any leakage past the'v-alve. The other 10 endof the bore 'I is reduced in diameter, as at I5, and is elptica] toconform to the cross sectional configuration of the lips Ill of theintake valve, so that the extent of opening of the lips is limited. l 15The valve in bore 8 is disposed oppositeto the other valve and opensoutward thus functioning as an outlet valve. 'I'he valve in bore 8 isheld in place by means of a ring-nut I6 threaded into the adjacentenlarged portion I2 of the bore and 20 engaging the adjacent flange I Ion the valve. An outlet fitting-I1 is threaded into the other end of thebore, to cooperate with the lips of the outlet valve. It is to be notedthat the valves are so mounted that the exterior of the lips I0 of the25 valves are free from engagement with any surrounding part whereby thelips may open and close with the reciprocation of plunger 6, the lips ofonly the intake valve opening on the intake stroke and the lips of onlythe outlet valve opening 30 in the compression stroke.

In use, the fitting I4 is connected to the usual tubing leading from thedonor while tting I'I is connected to the tubing leading to therecipient. Then, upon reciprocation of plunger 6, the blood 35 from thedonor is rst drawn into the syringe through the intake valve and thendischarged through the outlet valve into the tubing leading to therecipient. As the lips of the valves are normally closed due to theresiliency of the rub- 40 ber, no blood can regurgitate and it will onlyow in the intended direction upon opening of the valves in the desiredorder, i. e. the intake valve opening on the intake stroke and theoutlet valve on the compression stroke. With the compres- 45 sionstroke, the normally closed lips of the intake valve are further sealeddue to the pressure on the exterior of said lips.

When the transfusion is finished the syringe cap may be easilydisengaged from the syringe, the valves removed and the parts cleanedand sterilized. It is impossible to wrongly replace the valves, sincethe shape of the valves, relative to their bores or sockets in the cap,is such that the valves can only be mounted in one position.

From the foregoing description it will be readily seen that I haveproduced such a device as substantially fulfills the objects of theinvention as set forth herein. .u

While4 this specication sets forth in detail the present and preferredconstruction of the device, still in practice such deviations from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as dened by the appended claims.

Having thus described my invention, what I claim as new and useful anddesire to secure by LettersPatent is: Y

l. In a blood transfusion syringe, a syringe barrel, a cap mountedthereon, a pair of separate self contained identical check valvemembers, said members having tubular bodiesand being provided at one endwith resilient normally closed lips, the cap having inlet and outletpassages therethrough to. receive the valve bodies in snug fittingrelationship, the inlet passage being arranged to receive one of thevalves with its lip facing inwardly and the adjacent end of the inletpassage being restricted in size to allow of restricted separation ofthe lips; the outlet passage being arranged to receive/the other valvewith its lip facing outwardly, and a recipienttube coupling mounted onthe cap and having a threaded base screwed into the outerY end of theoutlet passage; said base having a recess in its inner end to receivethe lips of 4Vthe adjacent valve and of a size to allow of limitedopening movement of the lips.

2. In a blood transfusion syringe, a cap on the syringe, a, pair ofseparate self-contained and identical check valve members of tubularform arranged to allow of an unchecked iiow therethrough from one endonly, theY cap having inlet and outlet passages therethrough to receivethe check valves, and means formed with the check valves and cap toprovide for the mounting of the valves in the passages only in theproper posi-v tions to allow of an unchecked flow of blood into thesyringe through the inlet passage and out of the syringe through theoutlet passage; said means including an annular flange about each checkvalve at said one end thereof, an annular seat formed in the inletpassage adjacent its outer end to receive the ange of one valve and anannular seat in the outlet passage adjacent its inner end to receive theflange of the other valve.

f through from one end only, the cap having inlet and outlet Ypassagestherethrough to receive the check valves, donor and recipient tubecouplings mounted on the cap and communicating with the inlet and outletpassages respectively, an annular ange about each check valve at saidoneend thereof, an annular seat in the inlet passage adjacent its outer endto receive the flange of one valve, an annular seat in the outletpassage ad-` jacent its inner end to receive the flange of the othervalve, a ring threaded into the cap about the inner end of the outletpassage to engage and clamp the adjacent valve-flange in place, and athreaded base on the inner end of the donor cou-` pling to screw intothe outer end of the inlet passage to engage and clamp the adjacentvalveflange in place. Y

RICHARD P. LANDIS.

